AudioCodes Mediant 500 E-SBC User Manual page 318

Parameter
Web: Remote 3xx Behavior
CLI: sbc-rmt-3xx-behavior
[IpProfile_SBCRemote3xxBehavior]
User's Manual
b. The incoming INVITE is identified as a REFER-
resultant INVITE according to this special prefix.
c. The device replaces the host part in the Request-URI
with the host from the REFER contact. The special
prefix remains in the user part for regular
classification, manipulation, and routing. The special
prefix can also be used for specific routing rules for
REFER-resultant INVITEs.
d. The special prefix is removed before the resultant
INVITE is sent to the destination.

[2] IP Group Name = Sets the host part in the REFER
message to the name defined for the IP Group (in the IP
Group table).

[3] Handle Locally = Handles the incoming REFER
request itself without forwarding the REFER. The device
generates a new INVITE to the alternative destination
according to the rules in the IP-to-IP Routing table (the
'Call Trigger' field must be set to REFER).
Note: The corresponding global parameter is
SBCReferBehavior.
Defines the device's handling of SIP 3xx redirect responses
for this SIP entity. By default, the device's handling of SIP
3xx responses is to send the Contact header unchanged.
However, some SIP entities may support different versions
of the SIP 3xx standard while others may not even support
SIP 3xx.
When enabled, the device handles SIP redirections between
different subnets (e.g., between LAN and WAN sides). This
is required when the new address provided by the redirector
(Redirect sever) may not be reachable by the far-end user
(FEU) located in another subnet. For example, a far-end
user (FEU) in the WAN sends a SIP request via the device to
a Redirect server in the LAN, and the Redirect server replies
with a SIP 3xx response to a PBX in the LAN in the Contact
header. If the device sends this response as is (i.e., with the
original Contact header), the FEU is unable to reach the new
destination.

[0] Transparent = (Default) The device forwards the
received SIP 3xx response as is, without changing the
Contact header (i.e.,transparent handling).

[1] Database URL = The device changes the Contact
header so that the re-route request is sent through the
device. The device changes the URI in the Contact
header of the received SIP 3xx response to its own URI
and adds a special user prefix ("T~&R_"), which is then
sent to the FEU. The FEU then sends a new INVITE to
the device, which the device then sends to the correct
destination.

[2] Handle Locally = The device handles SIP 3xx
responses on behalf of the dialog-initiating UA and retries
the request (e.g., INVITE) using one or more alternative
URIs included in the 3xx response. The device sends the
new request to the alternative destination according to
the IP-to-IP Routing table (the 'Call Trigger' field must be
set to 3xx).
318
Mediant 500 E-SBC
Description
Document #: LTRT-10427